The present invention relates to an adapter for accommodating an optical connector, an optical module product including an optical connector, an adapter for the optical connector and an optical module, and an optical module mounting substrate product including the optical module product mounted onto a substrate.
A receptacle type optical module is known as an optical module. The optical module makes conversion such as opto-electric conversion, i.e., O/E conversion, or electro-optic conversion, i.e., E/O conversion. For the conversion, an optical fiber is optically connected to the optical module so as to receive and provide optical signals. This connection is made through a detachable/attachable connector.
As results of study on optical module products each including the optical module, the present inventors have found following problems. Are ceptacle type optical module includes a connector portion therein. An optical connector is directly mated to and unmated from this connector portion while connecting an end of an optical fiber. Thus, in the receptacle type optical module, external forces may be directly applied to the optical module itself when the optical connector is attached thereto or detached therefrom. The present inventors have found that the external forces may damage components in the optical module.
It is, therefore, an object of the present invention to provide an adapter, allowing external forces applied to an optical module to decrease when an optical connector is mated thereto or demated therefrom with a coated optical fiber connected to the optical connector, for an optical module connector, an optical module product including an optical module connector, and an optical module mounting substrate product on which the optical module product is mounted.
The adapter for an optical connector according to the present invention comprises a bottom portion and first and second wall portions. The bottom portion has a mounting surface that extends along a predetermined axis, and the mounting surface is provided so as to mount first and second optical connectors thereon. The first and second wall portions have respective inner wall surfaces thereof, each extending along a predetermined axis. The first and second wall portions are provided on the mounting surface such that one inner wall surface faces the other.
Preferably, the adapter for an optical connector can be applied to an optical module product comprising an optical module, a coated optical fiber, and a first optical connector. One end of the coated optical fiber is connected to this optical module. The other end of the coated optical fiber is connected to the first optical connector.
The adapter has a structure, providing the wall portions on the mounting surface, that makes it possible to accommodate the first optical connector provided along the direction vertical to the mounting surface and to accommodate the second optical connector provided along the predetermined axis. Thus, the second connector can be inserted in the predetermined axis direction to the accommodated first optical connector. The first optical connector is connected to the optical module through the coated optical fiber. Since the second optical connector is mated to and demated from this first optical connector, the external forces applied to the optical module, is decreased in mating and demating.
The bottom portion and the first and second wall portions are arranged to provide first and second opening portions. The first opening portion is opened in the direction vertical to the mounting surface so as to receive the first optical connector therefrom, and the second opening portion is opened in the predetermined axial direction so as to receive the second optical connector therefrom.
Since the adapter has a structure having the first opening portion and the second opening portion, the first connector can be inserted through the first opening portion of the adapter onto the mounting surface and then can be accommodated on the mounting surface while it is guided by both inner wall. The second connector is inserted through the second opening portion and then is introduced along both inner walls and the mounting surface of the adapter. Since the second connector is inserted while being guided by the adapter, the second connector can be mated to the first optical connector without damaging the coated optical fiber connected to the accommodated first optical connector.
The adapter further comprises a stopper. The stopper is provided so as to restrict a range where the first optical connector can move in the predetermined axial direction.
The stopper of the adapter defines a range within which the first optical connector can be disposed with respect to the predetermined axial direction. Specifically, even if the first optical connector is pushed by the second optical connector when the second optical connector is inserted along the predetermined axis to the adapter, the stopper restricts the movement range of the first optical connector. For example, since the stopper defines a limit point to which the first optical connector can move, the stopper can suppress a so-called ferrule back phenomenon of an optical connector. Since the stopper can reduce the force applied to the coated optical fiber by the moving first optical connector, the stress that may be applied to the coated optical fiber can be decreased. Further, it is ensured that the second connector is mated to the first optical connector.
In the adapter for an optical connector according to the present invention, the stopper can be provided such that the position of the stopper can be adjusted with respect to the predetermined axis direction. If the position of the stopper is adjusted, the adapter can be applied to various types of optical connectors. The position of the attached stopper can be adjusted in accordance with the configurations of the first and second optical connectors. Further, the adapter for an optical connector according to the present invention can be provided with at least one of a recess and a protrusion provided so as to adjust the position of the stopper with respect to the predetermined axial direction. The recess and protrusion above can be provided on each of the inner wall surfaces of the first and second wall portions. The recess and protrusion above also provide a simple structure, which enables the recess and/or the protrusion to engage with the stopper, that can restrict the movement of the optical connector. This simple structure results in the adapter having high reliability. Furthermore, when the recess and/or protrusion are employed, the stopper can be positioned with high precision in accordance with the positions of the recess and protrusion.
The adapter for an optical connector according to the present invention further comprises a third wall portion, extending in a direction intersecting with the predetermined axis, which is in contact with the first and second wall portions and the bottom portion.
The third wall portion functions as a stopper to the optical first connector. The third wall portion can include a cut portion. This cut portion is provided so as to introduce and guide the coated optical fiber connected to the first optical connector.
The adapter for an optical connector according to the present invention further comprises a lid, supported by the first and second wall portions, which can be provided so as to face the mounting surface. This lid can be provided so as to cover the first opening portion.
This lid, together with the mounting surface, can define the position of the optical connector with respect to the direction vertical to the mounting surface. On this account, it is possible to decrease bending of the optical fiber that may be caused by movement, in the adapter, of the connected or non-connected optical connector. The lid can protect the optical connectors arranged in the adapter, for example, the lid can prevent the optical connectors from directly contact with parts disposed around the optical connectors, and can provide dust-tight adapter. The lid can protect the optical connector against heat in a step of reflow soldering in manufacturing a optical module product.
In the adapter for an optical connector according to the present invention, the bottom portion has a latch portion. The latch portion is provided so as to extend opposite to the direction, with respect to the mounting surface, in which the first and second wall portions extend. The bottom portion may also include one or more latch portions. The latch portion facilitates the attachment of the adapter to the substrate.
Further, the adapter for an optical connector according to the present invention may have one or more additional features as described below.
In the adapter for an optical connector of the present invention, the lid may include a plurality of leg portions extending from the opposite sides of the lid. Each of the plurality of leg portions can include a projection engaging with the bottom portion of the adapter. Each of the first and second wall portions can include, on the respective outer surfaces of the wall portions, guide grooves for guiding the plurality of leg portions of the lid. This lid can have an inner wall surface provided so as to face the mounting surface. This inner wall surface can include a protruding portion so as to position the first and second connectors with respect to the direction vertical to the mounting surface. The inner wall surface can also include a guide portion for guiding the second connector with respect to its insertion direction. Further, the bottom portion has a plurality of latch portions, extending along an axis perpendicular to the mounting surface, on a bottom surface opposed to the mounting surface. Each of the plurality of latch portions includes a projection provided so as to be latched in a substrate to be attached.
An optical module product of the present invention comprises an optical module, an adapter for an optical connector, an optical fiber and a first optical connector. The optical module makes conversion in at least one of the following directions: the conversion from electric signals to optical signals; and the conversion from optical signals to electric signals. The optical connector is accommodated in the adapter. The optical fiber has a first end portion connected to the optical module and a second end portion connected to the optical connector. The optical module product according to the present invention has one of the adapter""s configurations that has already been described above and will be described below.
According to the optical module product, the adapter can hold the optical connector attached to one end of the optical fiber, the other end of which is connected with the optical module. The adapter can reduce the magnitudes of forces, such as bending forces, applied to the optical fiber.
For example, since the first optical connector can be provided on the mounting surface of the adapter in the direction vertical to the mounting surface through the first opening portion, the forces applied to the optical fiber can be reduced. Since the second optical connector is inserted through the second opening portion along the predetermined axis, i.e., in a direction of the optical axis of the first optical connector, to mate the first connector, these optical connectors can be easily mated to each other.
In the optical module product according to the present invention, the optical fiber can include a coating layer. The coating layer protects the optical fiber against forces that act thereon when the optical fiber contacts with peripheral components or the like. The coating layer can also protect the optical fiber against heat in a reflow soldering step of optical module product manufacture. Since the coating layer provides rigidity in the optical fiber, the amount of the optical fiber bending can be decreased even if forces is exerted on the optical fiber.
In the optical module product of the present invention, the coated layer may include a heat-shrinkable tubing adhered to the side surface of the optical fiber. The heat-shrinkable tube is easily adhered to the optical fiber to form the adhered coating layer. The heat-shrinkable tubing can also protect the coated optical fiber against heat added in the reflow soldering step because of the excellent heat resistance of the heat-shrinkable tubing. If the heat-shrinkable tubing is also provided around a portion of the optical fiber where bending is apt to occur, such as the connection portion of the optical fiber connected with the optical connector or optical module, the bending of the optical fiber can be decreased.
An optical module mounting substrate product according to the present invention comprises one or more optical module products and a substrate. The substrate has a conductive wiring layer. An optical module and an adapter are mounted on the substrate. The optical fiber has a first end portion connected to the optical module and a second end portion connected to an optical connector. The optical connector is accommodated in the adapter. The adapter may has one of the configurations that has already been described above and will be described below.
Since the second optical connector is mated to and unmated from the first connector that is accommodated in the adapter with the optical module connected to one end of the first connector, the accommodation prevents force from being directly exerted to the optical module in the mating and unmating it. This arrangement can decrease variation in characteristics of the optical module caused by the force exerted there to in mating the connectors. This allows the optical module to keep excellent characteristics for a long term.
The adapter receives the optical connector provided in the direction vertical to its mounting surface. This configuration makes it possible to shorten the length of the optical fiber to the same degree as the distance between the adapter and the optical module on the substrate while connecting the optical module with the optical connector. It is possible to reduce the length of the optical fiber necessary for arranging the optical connector in the adapter. Thus, the optical fiber does not have a surplus length that becomes unnecessary after the connectors are mated with each other. Since the optical fiber has no surplus length, this saves an area on the substrate required for placing the optical fiber tied together.
In the optical module mounting substrate product according to the present invention, an interval between the optical module and the adapter can be not less than 10 mm and not more than 40 mm. This distance is suitable for increasing the mounting density of the substrate.
In the optical module mounting substrate product according to the present invention, the optical module, the optical connector, the optical fiber and the adapter for the optical connector can be provided along the optical axis of the optical module product.
The optical module mounting substrate product according to the present invention includes 16 optical module products. Each of the optical module products is provided so as to face one side of the substrate.